Thermal interface material for integrated circuit package

Abstract

In an embodiment, a thermal interface material (TIM) is provided. The TIM includes first and a second layers of a first transition metal, and a third layer including a plurality of carbon nanotubes supported in a flexible polymer matrix and a second transition metal coupled to sidewalls of carbon nanotubes. The first and second metal layers are in contact with first and second ends of carbon nanotube. The TIM further includes fourth and fifth layers of an alloy material coupled to the first and second metal layers, respectively. The carbon nanotube based TIM including the layers with transition metal allow improved heat transfer from an integrated circuit die to a heat spreader.

What is claimed is: 
     
       1. A thermal interface material (TIM), comprising:
 first and second layers comprising a first metal; and 
 a third layer in contact with the first and second layers, comprising:
 a plurality of carbon nanotubes, wherein each carbon nanotube of the plurality of carbon nanotubes comprises a first end and a second end; 
 a second metal in contact with at least a portion of a sidewall of at least one carbon nanotube of the plurality of carbon nanotubes; and 
 a matrix material configured to provide flexible support to the plurality of carbon nanotubes. 
 
 
     
     
       2. The TIM of  claim 1 , further comprising:
 a fourth layer in contact with the first layer; and 
 a fifth layer in contact with the second layer, wherein each of the fourth and fifth layers comprises an alloy material. 
 
     
     
       3. The TIM of  claim 1 , wherein the second metal is in substantial contact with at least a portion of a sidewall of substantially all carbon nanotubes of the plurality of carbon nanotubes. 
     
     
       4. The TIM of  claim 1 , wherein each of the plurality of carbon nanotubes is configured to be substantially vertically aligned with one or more of the carbon nanotubes of the plurality of carbon nanotubes. 
     
     
       5. The TIM of  claim 1 , wherein the matrix material comprises a polymer material. 
     
     
       6. The TIM of  claim 1 , wherein the first metal comprises a transition metal selected from the group consisting of: titanium, niobium, and hafnium. 
     
     
       7. The TIM of  claim 1 , wherein the second metal comprises a transition metal selected from the group consisting of: titanium, nickel, and palladium. 
     
     
       8. The TIM of  claim 2 , wherein the alloy material comprises a low melting point alloy selected from the group consisting of: indium, tin, indium-tin, gallium, gold, tin-copper, tin-copper-silver, and tin-lead solder. 
     
     
       9. The TIM of  claim 1 , wherein the first metal is configured to covalently bond with the first and second ends of substantially all of the plurality of carbon nanotubes. 
     
     
       10. The TIM of  claim 1 , wherein each of the first and second layers is approximately 0.01 μm to 5 μm. 
     
     
       11. The TIM of  claim 1 , wherein each of the fourth and fifth layers is approximately 0.5 μm to 50 μm. 
     
     
       12. An integrated circuit (IC) package, comprising:
 a die; 
 a heat spreader; 
 a thermal interface material (TIM) coupled to the die and the heat spreader comprising:
 a plurality of carbon nanotubes; 
 a matrix material configured to support the plurality of carbon nanotubes; 
 first and second layers comprising a first transition metal coupled to one or more carbon nanotubes of the plurality of carbon nanotubes; and 
 a second transition metal in contact with at least a portion of a sidewall of at least one carbon nanotube of the plurality of the carbon nanotubes. 
 
 
     
     
       13. The IC package of  claim 12 , wherein the TIM further comprises:
 a third layer comprising a non-transition metal coupled to the heat spreader and the first layer; and 
 a fourth layer comprising a non-transition metal coupled to the die and the second layer. 
 
     
     
       14. The IC package of  claim 12 , wherein the second transition metal is coupled to at least a portion of a sidewall of substantially all carbon nanotubes of the plurality of carbon nanotubes. 
     
     
       15. The IC package of  claim 12 , wherein the matrix material comprises a polymer material. 
     
     
       16. The IC package of  claim 12 , wherein the matrix material comprises a low melting point alloy selected from the group consisting of: indium, tin, and indium-tin alloys. 
     
     
       17. A thermal interface material (TIM), comprising:
 a plurality of carbon nanotubes; 
 a matrix material configured to support the plurality of carbon nanotubes; 
 first and second layers comprising a first metal coupled to one or more carbon nanotubes of the plurality of carbon nanotubes; and 
 a second metal in contact with at least a portion of a sidewall of at least one carbon nanotube of the plurality of carbon nanotubes. 
 
     
     
       18. The TIM of  claim 17 , wherein the second metal is in substantial contact with at least a portion of a sidewall of substantially all carbon nanotubes of the plurality of carbon nanotubes. 
     
     
       19. The TIM of  claim 17 , wherein the first metal is configured to covalently bond with the first and second ends of substantially all of the plurality of carbon nanotubes. 
     
     
       20. The TIM of  claim 17 , further comprising:
 a third layer in contact with the first layer; and 
 a fourth layer in contact with the second layer, wherein each of the third and fourth layers comprises an alloy material.